DMTCS Proceedings, Automata 2011 - 17th International Workshop on Cellular Automata and Discrete Complex Systems

Font Size:  Small  Medium  Large

NOCAS : A Nonlinear Cellular Automata Based Stream Cipher

Sandip Karmakar, Dipanwita Roy Chowdhury

Abstract


LFSR and NFSR are the basic building blocks in almost all the state of the art stream ciphers like Trivium and Grain-128. However, a number of attacks are mounted on these type of ciphers. Cellular Automata (CA) has recently been chosen as a suitable structure for crypto-primitives. In this work, a stream cipher is presented based on hybrid CA. The stream cipher takes 128 bit key and 128 bit initialization vector (IV) as input. It is designed to produce 2{128} random keystream bits and initialization phase is made faster 4 times than that of Grain-128. We also analyze the cryptographic strength of this cipher. Finally, the proposed cipher is shown to be resistant against known existing attacks.

Full Text: PostScript PDF

Valid XHTML 1.0 Transitional